A Peek Into my Creative Process

I recently finished teaching my first class on glazes. Specifically, how to mix and test different colorants in glazes. This is something that I have wanted to do for a while. The nerd in me has always enjoyed testing and manipulating glazes, and within my local pottery guild, I saw a need for help with this subject.

After testing 153 different color combinations in a single base glaze, the last class was by far my favorite. This was the class where I attempted to pull it all together for my students, and hoped to pass on the glazing bug. In putting together the notes for this last class, I got to thinking about where to take all this information. What did I want my students to go home with?


I sorted through 8 years of tiles from my own glaze testing to bring in some of my more interesting results in an attempt to show my students how to proceed. What I really noticed, was how well it demonstrated my own creative process. And rather than try and explain it, I may as well show you.

Over the next few blog posts, I'll show you what I've been up to, and where it's taking my work. I currently seem to be going in a few different directions so forgive me if the posts jump around. What can I say? There's no telling where my brain takes itself...

Testin' Time Again...

Well, it's the time of year for me to break out all my glaze ingredients and go to town testing, testing, testing!

I recently unloaded 10 cubic feet of glaze tests and ...

Wait for it ...

not a single one gave me what I was looking for!

Glaze testing can be a colossal pain in the ass. I'm not going to lie. But it's a necessary evil. Before I fired this kiln load, I only had a vague idea of what I was looking for. Sort of...

I want another pair of colours to compliment my new line of work. Something simple, and earthy. Maybe a bit "warmer" than the slate gray and ice blue I'm currently working with.

 I had ideas in my head for a kind of warm, wheat colour in my matte glaze, and a nice, toasty merlot colour for my glossy liner. The paint chips here show the colour of matte glaze I am after in the center. It's called "Desert Fortress". (Am I the only one that thinks that's a pretty bizarre name for a colour?) But I digress...The merlot colour is shown on the right.

Since my ice blue is a stain, I thought 'what the hell' and got mason's 6006 to try after seeing some AMAZING results with it from a collegue of mine.

After that last firing, I can assure you that I have no interest in pursuing the 6006 stain. I used this base glaze, which meets all the requirements for a chrome/tin stain (CaO in 12 to 15%, zinc free) but alas, I was disappointed.I want to maintain a somewhat translucent glaze which can be tricky with stains, especially since this one has tin in it. To keep the translucence, I need the stain in percentages of 3 to 4%. Unfortunately, it was too low to give good colour. But any more than that, and I loose the depth and end up with very commercial looking, flat, opaque colours. Oh well...

Then there were the results for my matte glaze. I was using iron, nickel, rutile, titanium, and even tin and copper in various blends to get the wheaty colour I was searching for but to no avail. Most of the tests came out pretty ugly. I got lots of orange-y browns, fleshy colours but not that beautiful shade of "Desert Fortress".

 if you are interested in any of these colours, let me know, I'm happy to share...

There was however, some good news in all of this testing. I didn't get to see all of my results until after a visit I had with an incredibly talented potter, Iris Dorton. We had a long chat about all things pottery when I went to visit her in her fabulous new studio. She has a stunning new line of work and I was picking her brain on how she made this transition. She was quick to point out that her new line of work uses the same colours and compliments her old line of work. This should have been obvious. My new colours and forms are such a HUGE departure from my arabesque collection that I had no idea how to tie the two lines together.


After this visit, and then unloading my kiln to see all these tests, it finally came together. I am going to bring my purpley-blue glaze over to the new collection of work for my glossy liner, and work on the wheat colour I'm after for the matte glaze.
 
 Seeing all of my test results, I can extrapolate and have a much better understanding of the blends necessary to get the colour I'm after.
 So some fine tuning and I'm confident I can get what I want. And I think the two colours will not only look smashing together, but will help to bring the two lines of work together. So stay tuned for some more testing....

Singing the Test Tile Blues

It's that time of year again. Test tiles.

You may recall, I've been working out ideas for a new line of work for quite some time now. This past Christmas things finally came together and I unveiled this new line at my recent wholesale show in Toronto.

Getting it ready for the show, unfortunately, was quite the ordeal. I was struggling to find a nice, clear, durable glaze that I could use with this one that I had been working on a while back. I had a very specific color in mind and set about testing, testing, and testing some more to achieve it. Robin's egg blue. Maybe a bit more of the blue, less of the turquoise, but just to give you an idea. And I had an idea of where to start with my testing. Copper, maybe a fraction of a percent of cobalt to punch it to the blue side...

My guesses were pretty good and in my first batch of test tiles I hit the color I was looking for: 1% copper carbonate plus 0.1% cobalt carbonate. So I set about mixing up a slightly larger batch to get it on some work. It's always easier to get a real feel for a glaze by testing larger batches, rather than just mixing up a huge bucket from what you see on a test tile. Annnnnnd.... I'm glad I did.

Disaster. Super ICK. Bubbles! Everywhere, thousands and thousands of bubbles! My beautiful, clear, glossy glaze was dulled with a pitted surface and microscopic bubbles everywhere. Test tiles are far too small to get an accurate picture of what a glaze will do, and in this case, what the glaze did on a plate, was much different that what it did on a tile.

So. I hit the books. Copper gives off gas after 1975' or so. (Don't quote me on that temperature though, I'm not sure exactly where it starts to get volatile). All that gas was getting trapped in my glaze, even with a hold at peak temperature. Okay. No problem. The carbonate form of copper can release more gas that the oxide form so I mixed up some more tests, using 0.65% copper oxide instead of the carbonate. (The oxide is a stronger colorant). But alas, the bubbles persisted.

Okay. No problem. Tinker with the glaze recipe a bit and I should be able to fix that, right? Working with my Insight program, I tried adding 2% lithium carbonate to the glaze as a way to smooth out the surface. And it worked! But now instead of a beautiful, clear glaze, I had a beautiful, variegated glaze.

Okay. No problem. Back to the Insight program. I removed the lithium and decided to tackle the alumina. I was able to lower the alumina content of my glaze to make it a bit runnier, the idea being that if the glaze flows and moves better, those pesky little bubbles will be able to escape.

Annnnnd, it worked! but now I had yet another problem. Boron clouding. Ugh. The alumina keeps the glaze stiff which prevents boron crystals from forming. Without the alumina, the crystals were able to grow. That means, no clear glaze for me.



With the clock ticking and me needing to resolve this issue, I turned to stains. Yes. Stains. Something I had sworn I would never use. Something I had always considered as a form of cheating. With my head hanging low, I ordered several different shades of what looked like promising colors and went back to mixing up test batches.



The first bunch of tests gave me an idea of how each stain looked. From there, I was able to put together some blends that I thought would push the color to where I wanted it. And as luck would have it, the next batch gave me just what I was looking for.



Actually, it gave me better than what I was looking for. I have a whole new respect for those stains, let me tell ya'. And I may just be turning to them a lot more in the future.

And as for that new line of work...
You may be wondering why it's so different from where my tests began so many months ago. What can I say? There's no telling where creative adventures will take us. I can say, however, that I'm really pleased with how the new line looks!